2011-06-23 35 views

回答

3

在过去,我写了完全一样的东西。然后我删除它。此版本使用准备好的代码在缩放时曝光图像。它取自Jack Valmadre’s Blog

#!/usr/bin/python 
# -*- coding: utf-8 -*- 
# 
# Taken and customed from Jack Valmadre's Blog: 
# http://jackvalmadre.wordpress.com/2008/09/21/resizable-image-control/ 
# 
# Put together and created the time switching by Izidor Matusov <[email protected]> 

import os 

import pygtk 
pygtk.require('2.0') 
import gtk 
import glib 

def is_image(filename): 
    """ File is image if it has a common suffix and it is a regular file """ 

    if not os.path.isfile(filename): 
     return False 

    for suffix in ['.jpg', '.png', '.bmp']: 
     if filename.lower().endswith(suffix): 
      return True 

    return False 

def resizeToFit(image, frame, aspect=True, enlarge=False): 
    """Resizes a rectangle to fit within another. 

    Parameters: 
    image -- A tuple of the original dimensions (width, height). 
    frame -- A tuple of the target dimensions (width, height). 
    aspect -- Maintain aspect ratio? 
    enlarge -- Allow image to be scaled up? 

    """ 
    if aspect: 
     return scaleToFit(image, frame, enlarge) 
    else: 
     return stretchToFit(image, frame, enlarge) 

def scaleToFit(image, frame, enlarge=False): 
    image_width, image_height = image 
    frame_width, frame_height = frame 
    image_aspect = float(image_width)/image_height 
    frame_aspect = float(frame_width)/frame_height 
    # Determine maximum width/height (prevent up-scaling). 
    if not enlarge: 
     max_width = min(frame_width, image_width) 
     max_height = min(frame_height, image_height) 
    else: 
     max_width = frame_width 
     max_height = frame_height 
    # Frame is wider than image. 
    if frame_aspect > image_aspect: 
     height = max_height 
     width = int(height * image_aspect) 
    # Frame is taller than image. 
    else: 
     width = max_width 
     height = int(width/image_aspect) 
    return (width, height) 

def stretchToFit(image, frame, enlarge=False): 
    image_width, image_height = image 
    frame_width, frame_height = frame 
    # Stop image from being blown up. 
    if not enlarge: 
     width = min(frame_width, image_width) 
     height = min(frame_height, image_height) 
    else: 
     width = frame_width 
     height = frame_height 
    return (width, height) 


class ResizableImage(gtk.DrawingArea): 

    def __init__(self, aspect=True, enlarge=False, 
      interp=gtk.gdk.INTERP_NEAREST, backcolor=None, max=(1600,1200)): 
     """Construct a ResizableImage control. 

     Parameters: 
     aspect -- Maintain aspect ratio? 
     enlarge -- Allow image to be scaled up? 
     interp -- Method of interpolation to be used. 
     backcolor -- Tuple (R, G, B) with values ranging from 0 to 1, 
      or None for transparent. 
     max -- Max dimensions for internal image (width, height). 

     """ 
     super(ResizableImage, self).__init__() 
     self.pixbuf = None 
     self.aspect = aspect 
     self.enlarge = enlarge 
     self.interp = interp 
     self.backcolor = backcolor 
     self.max = max 
     self.connect('expose_event', self.expose) 
     self.connect('realize', self.on_realize) 

    def on_realize(self, widget): 
     if self.backcolor is None: 
      color = gtk.gdk.Color() 
     else: 
      color = gtk.gdk.Color(*self.backcolor) 

     self.window.set_background(color) 

    def expose(self, widget, event): 
     # Load Cairo drawing context. 
     self.context = self.window.cairo_create() 
     # Set a clip region. 
     self.context.rectangle(
      event.area.x, event.area.y, 
      event.area.width, event.area.height) 
     self.context.clip() 
     # Render image. 
     self.draw(self.context) 
     return False 

    def draw(self, context): 
     # Get dimensions. 
     rect = self.get_allocation() 
     x, y = rect.x, rect.y 
     # Remove parent offset, if any. 
     parent = self.get_parent() 
     if parent: 
      offset = parent.get_allocation() 
      x -= offset.x 
      y -= offset.y 
     # Fill background color. 
     if self.backcolor: 
      context.rectangle(x, y, rect.width, rect.height) 
      context.set_source_rgb(*self.backcolor) 
      context.fill_preserve() 
     # Check if there is an image. 
     if not self.pixbuf: 
      return 
     width, height = resizeToFit(
      (self.pixbuf.get_width(), self.pixbuf.get_height()), 
      (rect.width, rect.height), 
      self.aspect, 
      self.enlarge) 
     x = x + (rect.width - width)/2 
     y = y + (rect.height - height)/2 
     context.set_source_pixbuf(
      self.pixbuf.scale_simple(width, height, self.interp), x, y) 
     context.paint() 

    def set_from_pixbuf(self, pixbuf): 
     width, height = pixbuf.get_width(), pixbuf.get_height() 
     # Limit size of internal pixbuf to increase speed. 
     if not self.max or (width < self.max[0] and height < self.max[1]): 
      self.pixbuf = pixbuf 
     else: 
      width, height = resizeToFit((width, height), self.max) 
      self.pixbuf = pixbuf.scale_simple(
       width, height, 
       gtk.gdk.INTERP_BILINEAR) 
     self.invalidate() 

    def set_from_file(self, filename): 
     self.set_from_pixbuf(gtk.gdk.pixbuf_new_from_file(filename)) 

    def invalidate(self): 
     self.queue_draw() 

class DemoGtk: 

    SECONDS_BETWEEN_PICTURES = 3 
    FULLSCREEN = True 
    WALK_INSTEAD_LISTDIR = True 

    def __init__(self): 
     self.window = gtk.Window() 
     self.window.connect('destroy', gtk.main_quit) 
     self.window.set_title('Slideshow') 

     self.image = ResizableImage(True, True, gtk.gdk.INTERP_BILINEAR) 
     self.image.show() 
     self.window.add(self.image) 

     self.load_file_list() 

     self.window.show_all() 

     if self.FULLSCREEN: 
      self.window.fullscreen() 

     glib.timeout_add_seconds(self.SECONDS_BETWEEN_PICTURES, self.on_tick) 
     self.display() 

    def load_file_list(self): 
     """ Find all images """ 
     self.files = [] 
     self.index = 0 

     if self.WALK_INSTEAD_LISTDIR: 
      for directory, sub_directories, files in os.walk('.'): 
       for filename in files: 
        if is_image(filename): 
         filepath = os.path.join(directory, filename) 
         self.files.append(filepath) 
     else: 
      for filename in os.listdir('.'): 
       if is_image(filename): 
        self.files.append(filename) 

     print "Images:", self.files 

    def display(self): 
     """ Sent a request to change picture if it is possible """ 
     if 0 <= self.index < len(self.files): 
      self.image.set_from_file(self.files[self.index]) 
      return True 
     else: 
      return False 

    def on_tick(self): 
     """ Skip to another picture. 

     If this picture is last, go to the first one. """ 
     self.index += 1 
     if self.index >= len(self.files): 
      self.index = 0 

     return self.display() 

if __name__ == "__main__": 
    gui = DemoGtk() 
    gtk.main() 

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